Tunable luminescence of broadband-excited and narrow line green emitting Y2SiO5:Ce3+, Tb3+ phosphor

Abstract Cerium and terbium activated white emitting yttrium silicate phosphors (Y 2−x − y Ce x Tb y SiO 5 ) having average size between 96 and 123 nm were synthesised by a gel-combustion, and their phase and crystal structures, morphologies and ultraviolet (UV)-visible spectroscopic properties were studied. All rare earth doped yttrium silicate (YSO) phosphors are well crystallized powders containing only monoclinic X2-Y 2 SiO 5 phase. No significant changes in the cell parameters were observed with increasing of Tb amount as ionic radii of Tb 3+ (0.923 A) and Y 3+ (0.9 A) have almost the same. Under different excitations, YSO:Ce 3+ exhibits blue emission due to the 5d–4f transitions of Ce 3+ ions. The series of emission states at different wavelengths of YSO:Tb 3+ associated to f – f transition of Tb 3+ ion were detected from luminescence measurements. The emission observed at 544 nm (green) corresponding to 5 D 4  →  7 F 5 of Tb 3+ is strongest one. Incorporation of variable amounts of Tb 3+ in the YSO host lattice determines the modification of emission colour from blue through light blue and eventually to bluish green. A possible energy transfer mechanism taking place from Ce 3+ to Tb 3+ was also discussed in terms of excitation and emission spectra.